Can Adult Cats Eat Kitten Food? Everything You Absolutely Need to Know

Siamese cat with blue glasses asking can adult cats eat kitten food

Q: Can adult cats eat kitten food?

A: Yes, but most vets and food manufacturers don’t recommend it because kitten food is very calorie-dense. It can make healthy adult cats overweight. But there are some instances when adult cats can eat kitten food.

If you have a pregnant, lactating cat, or senior cat, feeding them kitten food can help them maintain their health.

Out diet greatly affects our health, and the same is so with your feline friends. Adult cats’ nutritional needs are different from kittens’. Adult and senior cats need adult cat food to stay healthy.

Kitten food has higher levels of protein and nutrients for their development that support the rapid growth of baby cats. Extra protein helps the development of muscle growth and overall health.

So, here’s everything you need to know about adult cat food and kitten food and when your adult cat can eat kitten food.

can adult cats eat kitten food adult leopard print cat

What is the Difference Between Kitten Food and Cat Food?

Little kittens require more nutrients and protein than adult kitties, so kitten food addresses this need. So kitten food contains all the vital nutrients and proteins they need for healthy growth.

Most cats are considered adults after they reach 12 months of age, but some breeds don’t reach full maturity until later. So, depending on your cat’s breed, they may eat kitten food longer.

However, the extra calories and protein in kitten food may put on extra pounds for most indoor cats. 

can adult cats eat kitten food gray cat at table

When Should I Switch from Kitten Food to Adult Cat Food?

Most cats are considered kittens until they reach 12 months of age, but when they stop growing depends on their breed. Large cat breeds like the Maine Coon can take between 18 months to two years of age to fully mature. 

Experts recommend feeding your cat high-quality kitten food until they are around a year old, then you can switch them to adult cat food.

But once your cat reaches full maturity, you need to switch them to adult cat food as kittens require more protein and calories because of how energetic they are. Plus, they are growing.

Adult cats are less energetic and don’t need the same amounts of nutrients and protein that kittens do.

To ensure that your cat doesn’t have any intestinal problems, it’s best to switch them gradually from kitten formula to adult cat food.

Iams advises you to use the following schedule to switch them over:

  • Day One: Fill your cat’s dish with 75% kitten food and 25% adult food.
  • Day Two: Mix adult and kitten food in a 50/50 ratio.
  • Day Three: Feed your cat a mixture that’s 75% adult food and 25% kitten food.
  • Day Four: Switch to 100% adult formula.

When Can Kittens Start Eating Wet and Dry Food?

Kittens should not eat adult cat food until they reach maturity, but they can start eating wet and dry kitten food much earlier.

By the time they are three or four weeks old, they can start eating wet food or moistened dry kibble. Once they are fully weaned from their mothers between six and eight weeks old, they can begin eating dry or wet kitten food

Here’s a helpful video on dry cat food vs. wet cat food.

How Many Calories a Day Does My Adult Cat Need?

The quick answer is that a 10-pound adult cat needs about 270 calories a day, depending on activity levels, to maintain a sleek, healthy coat and physique. When answering the question, can adult cats eat kitten food, it’s important to calculate how many calories a day your cat needs.

In addition, cat food is prepared differently for every cat age group, from kittens to senior cats, based on their dietary needs.

The math to calculate the number of calories your cat needs per day is as follows:

[30 x (ideal body weight in kilograms)] + 70]

First, convert your cat’s weight to kilograms by dividing their weight by 2.2. So, if your cat weighs 12 lbs their weight in kilograms is 

12 lbs ÷ 2.2  = 5.45

[30 x 5.5] + 70 = 233 calories a day to maintain that weight

Adult cats that spend their days indoors may need fewer calories, and outdoor or highly active cats may need more. However, not all calories are quality calories.

For example, dry cat food may not have the calorie content your cat needs due to its higher carbohydrate (cereal) content. Once you learn the number of calories your cat needs a day, then you can figure out how to give them those calories.

four cats in a row eating from food bowls

How Do Fatty Acids and the Fat Content in Food Affect My Cat’s Health?

Cats get their energy from protein and fat. Dietary protein contains ten different amino acids that dogs and cats can’t create on their own. These essential amino acids supply the building blocks for many vital biologically active proteins and compounds.

Deficiencies in even just one amino acid can lead to severe health problems in cats. Dietary fats in cat food are primarily derived from seed oils and animal fats, which are critical parts of a cat’s diet. 

Dietary fat is necessary for energy as it provides double the amount that carbohydrates or protein do.

Unlike humans, research has shown that high-fat diets don’t seem to have any negative impact on a healthy cat’s cholesterol as long as their daily calorie intake remains consistent. Their food should contain a fat content of no less than 9 percent of dry matter.

If your cat needs to lose weight, its diet will contain less fat compared to food designed to maintain a cat’s weight.

Essential fatty acids are necessary for a sleek shiny coat and healthy skin, as well as the energy they provide. These nutrients provide the essential group of omega-fatty acids, including Omega-3s, which is necessary for your cat’s nervous system development and health.

Omega-6 fatty acid supports the function of your kitty’s liver, muscle, and kidney function. 

So knowing your kitty’s needs will help you keep them healthy. You’ll know just what to look for in their foods.

can adult cats eat kitten food orange tabby on a blanket

What are Your Cat’s Protein Needs?

Cats need a lot more protein in their diet than humans or dogs. Adult dogs only need a minimum of 12 percent of protein in their diet, humans need 8 percent, but 35-40 percent of a cat’s diet needs to be protein.

Wet food tends to have more protein than dry food. 

Cats need a minimum of two grams of protein per pound of body weight.

The quality of the protein you give your feline friends is very important. If in the wild, they would be catching mice, squirrels, rabbits, and insects to survive. Protein, not cereal, is the mainstay of their ancestor’s diets.

They will eat grass and catmint, but they really need protein. High-quality cat food will keep your kitty healthy by providing the nutrients it needs.

cat licking mouth in front of food bowl

What Vitamins and Minerals Do My Adult Cats Need?

Your cats need six essential vitamins in their diets. These nutrients are listed on cat food packages and include:


  • Vitamin A – crucial for eye and immune system health
  • Vitamin D – balances calcium and phosphorus in your cat’s body
  • B1 (thiamin) aids the metabolism of carbohydrates.
  • B2 (riboflavin) needed for growth and overall health
  • B3 (niacin) is required for the health of the nervous and gastrointestinal systems.
  • B6 (pyridoxine) is crucial for the health of your cats’ red blood cells and immune system function.


  • Calcium – essential to bone growth, muscle function, nerve impulse transmission
  • Chloride – helps your cat’s body maintain a proper pH balance
  • Iron – deficiency can cause many illnesses
  • Magnesium – aids the absorption of other minerals
  • Sodium – helps transfer nutrients from cell to cell and aids in the elimination of waste products.
orange tabby kitten eating kibble

Can Kitten Food Be Beneficial to Adult Cats?

Yes, there are some instances when adult cats can eat kitten food.

Can Senior Cat’s Eat Kitten Food?

Older cats can be fussy about eating, and they can lose muscle mass with age and develop medical conditions that require a special diet. However, increased protein can help them maintain a healthy weight. So, feeding your senior cat kitten food can help your old kitty gain weight.

However, adult cats can develop chronic kidney disease, and the high protein of kitten food can aggravate this health issue. Although others claim the problem with our cat’s kidneys is not protein but phosphorus in our cat’s diets.

If you find your senior cat is losing muscle mass, the best thing you can do is consult your veterinarian. They’ll be able to help you come up with a diet plan for your older cat.

can adult cats eat kitten food light colored cat and gray kitten

Can Pregnant and Lactating Cats Eat Kitten Food?

A pregnant or lactating cat can use the extra nutrients of kitten food due to the massive calories she grows multiple kittens or nursing them. Plus, it will also help her litter when it comes time to switch them to solid food as they’ll copy what she does.

How to Introduce an Adult Cat to Kitten Food for the First Time

If you need to give your adult cat kitten food, give them a little at a time, several times a  day. Your cats should ideally eat three to four times a day, and if you do this, they won’t get hungry. You will also be able to tell, rather quickly, if the higher protein content is upsetting their stomach.

Can Kitten Food Cause Diarrhea in Adult Cats?

Once you figure out the answer to the question can adult cats eat kitten food, you probably want to know if there are any side effects like diarrhea. Any new food your cat eats can cause diarrhea if it is sensitive to or can’t digest one of the ingredients. Sometimes cats can develop a hypersensitivity to a food source even if they’ve eaten it for a long time with no problems.

Eating human food and toxins can also produce diarrhea. All cats have upset stomachs from time to time. If it continues after changing food, discontinue its use and return to what you were feeding them to see if your kitty gets better. Continuous diarrhea can be a sign of an illness instead of a food issue. It would help if you saw your veterinarian.

orange and white kitten

Can Kittens Eat Adult Cat Food?

Kittens need the higher protein and fat content of kitten food. However, some foods are labeled ‘for all life stages’, but you shouldn’t feed these foods to your kitten unless there are feeding tests that support that claim.

FAQs in neon yellow


Do cats get bored of eating the same food every day?

Yes, cats can get bored eating the same food every day, and they need variety. Mix up your cat’s variety by giving them wet and dry food. You may eventually need to switch to a different type of food over time, so they don’t get bored.

Why is my adult cat only eating kitten food?

You may be asking can adult cats eat kitten food because your adult cat will only eat kitten food. Your cat may be eating it for the taste or because it is available. Try to feed your kittens and adult cats separately if that’s the issue because a kitten food diet is more calorie-dense and can make your adult cat overweight.

What happens if my kitten eats my older cat’s food?

While a little bit of adult cat food won’t hurt your kitten, feeding her only adult food won’t give them all the nutrients and protein they need to grow.

Kittens need more calories and protein to grow up healthy, but their stomachs aren’t very large. Therefore, the easiest way to make sure kittens get the protein and calories they need is to make kitten food more calorie-dense.

You’ll find that most cat foods tell you right on the label what age the food is most suitable for. When in doubt, always check cat food labels or go by the manufacturer’s recommendations.

can adult cats eat kitten food white and brown cat eating wet food

Final Thoughts on Can Adult Cats Eat Kitten Food

Can adult cats eat kitten food? In general, a healthy adult cat should not eat kitten food unless they are pregnant, lactating, or a senior. Even if they are picky eaters, eating kitten food could make them overweight. Feeding a senior cat kitten food could help them gain muscle mass or weight if they lose it. And the calories and protein it has are perfect for cat mothers who burn an incredible amount of calories while pregnant or nursing.

Each cat’s life stage has different nutritional requirements, so choosing the right for your cat’s age is critical. You’ll find many different types of foods for cats and kittens on the market, from canned food to dry food for cats’ different life stages. Whatever food your cat needs, make sure it’s made with high-quality ingredients.

Before you feed your adult cat kitten food, make sure to consult your veterinarian. They can advise the best diet plan for your kitten or adult cat, whether weight loss or weight gain is the primary goal. It’s important for cats of all ages to maintain an ideal weight because being overweight or underweight can cause serious health problems.

Now you know the answer to the question, can adult cats eat kitten food?

2 thoughts on “Can Adult Cats Eat Kitten Food? Everything You Absolutely Need to Know”

  1. So interesting! I have 3 cats and didn’t know all of this. Two of ours are on special urinary food, while the third is a big boy and needs to be put on a diet…but he loves to go around pigging out on everyone else’s food when they walk away. Strangely, he doesn’t care at all about table scraps, though!

    1. HAHAHA I love that your “big boy” likes to go around pigging out on everyone else’s food because MY cat would do this if there were other cats in the house. He needs to go on a diet too some I the vet told me to get one of the Doc and Phoebe Indoor Hunting Feeder! Glad the post was helpful. 🙂

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